<?php

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	exit ( 'No direct script access allowed' );
/**
 * CodeIgniter
 *
 * An open source application development framework for PHP 5.1.6 or newer
 *
 * @package		CodeIgniter
 * @author		ExpressionEngine Dev Team
 * @copyright	Copyright (c) 2008 - 2011, EllisLab, Inc.
 * @license		http://codeigniter.com/user_guide/license.html
 * @link		http://codeigniter.com
 * @since		Version 1.0
 * @filesource
 */

// ------------------------------------------------------------------------


/**
 * Output Class
 *
 * Responsible for sending final output to browser
 *
 * @package		CodeIgniter
 * @subpackage	Libraries
 * @category	Output
 * @author		ExpressionEngine Dev Team
 * @link		http://codeigniter.com/user_guide/libraries/output.html
 */
class CI_Output {
	
	protected $final_output;
	protected $cache_expiration = 0;
	protected $headers = array ();
	protected $mime_types = array ();
	protected $enable_profiler = FALSE;
	protected $_zlib_oc = FALSE;
	protected $_profiler_sections = array ();
	protected $parse_exec_vars = TRUE; // whether or not to parse variables like {elapsed_time} and {memory_usage}
	

	function __construct() {
		$this->_zlib_oc = @ini_get ( 'zlib.output_compression' );
		
		// Get mime types for later
		if (defined ( 'ENVIRONMENT' ) and file_exists ( APPPATH . 'config/' . ENVIRONMENT . '/mimes.php' )) {
			include APPPATH . 'config/' . ENVIRONMENT . '/mimes.php';
		} else {
			include APPPATH . 'config/mimes.php';
		}
		
		$this->mime_types = $mimes;
		
		log_message ( 'debug', "Output Class Initialized" );
	}
	
	// --------------------------------------------------------------------
	

	/**
	 * Get Output
	 *
	 * Returns the current output string
	 *
	 * @access	public
	 * @return	string
	 */
	function get_output() {
		return $this->final_output;
	}
	
	// --------------------------------------------------------------------
	

	/**
	 * Set Output
	 *
	 * Sets the output string
	 *
	 * @access	public
	 * @param	string
	 * @return	void
	 */
	function set_output($output) {
		$this->final_output = $output;
		
		return $this;
	}
	
	// --------------------------------------------------------------------
	

	/**
	 * Append Output
	 *
	 * Appends data onto the output string
	 *
	 * @access	public
	 * @param	string
	 * @return	void
	 */
	function append_output($output) {
		if ($this->final_output == '') {
			$this->final_output = $output;
		} else {
			$this->final_output .= $output;
		}
		
		return $this;
	}
	
	// --------------------------------------------------------------------
	

	/**
	 * Set Header
	 *
	 * Lets you set a server header which will be outputted with the final display.
	 *
	 * Note:  If a file is cached, headers will not be sent.  We need to figure out
	 * how to permit header data to be saved with the cache data...
	 *
	 * @access	public
	 * @param	string
	 * @return	void
	 */
	function set_header($header, $replace = TRUE) {
		// If zlib.output_compression is enabled it will compress the output,
		// but it will not modify the content-length header to compensate for
		// the reduction, causing the browser to hang waiting for more data.
		// We'll just skip content-length in those cases.
		

		if ($this->_zlib_oc && strncasecmp ( $header, 'content-length', 14 ) == 0) {
			return;
		}
		
		$this->headers [] = array ($header, $replace );
		
		return $this;
	}
	
	// --------------------------------------------------------------------
	

	/**
	 * Set Content Type Header
	 *
	 * @access	public
	 * @param	string	extension of the file we're outputting
	 * @return	void
	 */
	function set_content_type($mime_type) {
		if (strpos ( $mime_type, '/' ) === FALSE) {
			$extension = ltrim ( $mime_type, '.' );
			
			// Is this extension supported?
			if (isset ( $this->mime_types [$extension] )) {
				$mime_type = & $this->mime_types [$extension];
				
				if (is_array ( $mime_type )) {
					$mime_type = current ( $mime_type );
				}
			}
		}
		
		$header = 'Content-Type: ' . $mime_type;
		
		$this->headers [] = array ($header, TRUE );
		
		return $this;
	}
	
	// --------------------------------------------------------------------
	

	/**
	 * Set HTTP Status Header
	 * moved to Common procedural functions in 1.7.2
	 *
	 * @access	public
	 * @param	int		the status code
	 * @param	string
	 * @return	void
	 */
	function set_status_header($code = 200, $text = '') {
		set_status_header ( $code, $text );
		
		return $this;
	}
	
	// --------------------------------------------------------------------
	

	/**
	 * Enable/disable Profiler
	 *
	 * @access	public
	 * @param	bool
	 * @return	void
	 */
	function enable_profiler($val = TRUE) {
		$this->enable_profiler = (is_bool ( $val )) ? $val : TRUE;
		
		return $this;
	}
	
	// --------------------------------------------------------------------
	

	/**
	 * Set Profiler Sections
	 *
	 * Allows override of default / config settings for Profiler section display
	 *
	 * @access	public
	 * @param	array
	 * @return	void
	 */
	function set_profiler_sections($sections) {
		foreach ( $sections as $section => $enable ) {
			$this->_profiler_sections [$section] = ($enable !== FALSE) ? TRUE : FALSE;
		}
		
		return $this;
	}
	
	// --------------------------------------------------------------------
	

	/**
	 * Set Cache
	 *
	 * @access	public
	 * @param	integer
	 * @return	void
	 */
	function cache($time) {
		$this->cache_expiration = (! is_numeric ( $time )) ? 0 : $time;
		
		return $this;
	}
	
	// --------------------------------------------------------------------
	

	/**
	 * Display Output
	 *
	 * All "view" data is automatically put into this variable by the controller class:
	 *
	 * $this->final_output
	 *
	 * This function sends the finalized output data to the browser along
	 * with any server headers and profile data.  It also stops the
	 * benchmark timer so the page rendering speed and memory usage can be shown.
	 *
	 * @access	public
	 * @return	mixed
	 */
	function _display($output = '') {
		// Note:  We use globals because we can't use $CI =& get_instance()
		// since this function is sometimes called by the caching mechanism,
		// which happens before the CI super object is available.
		global $BM, $CFG;
		
		// Grab the super object if we can.
		if (class_exists ( 'CI_Controller' )) {
			$CI = & get_instance ();
		}
		
		// --------------------------------------------------------------------
		

		// Set the output data
		if ($output == '') {
			$output = & $this->final_output;
		}
		
		// --------------------------------------------------------------------
		

		// Do we need to write a cache file?  Only if the controller does not have its
		// own _output() method and we are not dealing with a cache file, which we
		// can determine by the existence of the $CI object above
		if ($this->cache_expiration > 0 && isset ( $CI ) && ! method_exists ( $CI, '_output' )) {
			$this->_write_cache ( $output );
		}
		
		// --------------------------------------------------------------------
		

		// Parse out the elapsed time and memory usage,
		// then swap the pseudo-variables with the data
		

		$elapsed = $BM->elapsed_time ( 'total_execution_time_start', 'total_execution_time_end' );
		
		if ($this->parse_exec_vars === TRUE) {
			$memory = (! function_exists ( 'memory_get_usage' )) ? '0' : round ( memory_get_usage () / 1024 / 1024, 2 ) . 'MB';
			
			$output = str_replace ( '{elapsed_time}', $elapsed, $output );
			$output = str_replace ( '{memory_usage}', $memory, $output );
		}
		
		// --------------------------------------------------------------------
		

		// Is compression requested?
		if ($CFG->item ( 'compress_output' ) === TRUE && $this->_zlib_oc == FALSE) {
			if (extension_loaded ( 'zlib' )) {
				if (isset ( $_SERVER ['HTTP_ACCEPT_ENCODING'] ) and strpos ( $_SERVER ['HTTP_ACCEPT_ENCODING'], 'gzip' ) !== FALSE) {
					ob_start ( 'ob_gzhandler' );
				}
			}
		}
		
		// --------------------------------------------------------------------
		

		// Are there any server headers to send?
		if (count ( $this->headers ) > 0) {
			foreach ( $this->headers as $header ) {
				@header ( $header [0], $header [1] );
			}
		}
		
		// --------------------------------------------------------------------
		

		// Does the $CI object exist?
		// If not we know we are dealing with a cache file so we'll
		// simply echo out the data and exit.
		if (! isset ( $CI )) {
			echo $output;
			log_message ( 'debug', "Final output sent to browser" );
			log_message ( 'debug', "Total execution time: " . $elapsed );
			return TRUE;
		}
		
		// --------------------------------------------------------------------
		

		// Do we need to generate profile data?
		// If so, load the Profile class and run it.
		if ($this->enable_profiler == TRUE) {
			$CI->load->library ( 'profiler' );
			
			if (! empty ( $this->_profiler_sections )) {
				$CI->profiler->set_sections ( $this->_profiler_sections );
			}
			
			// If the output data contains closing </body> and </html> tags
			// we will remove them and add them back after we insert the profile data
			if (preg_match ( "|</body>.*?</html>|is", $output )) {
				$output = preg_replace ( "|</body>.*?</html>|is", '', $output );
				$output .= $CI->profiler->run ();
				$output .= '</body></html>';
			} else {
				$output .= $CI->profiler->run ();
			}
		}
		
		// --------------------------------------------------------------------
		

		// Does the controller contain a function named _output()?
		// If so send the output there.  Otherwise, echo it.
		if (method_exists ( $CI, '_output' )) {
			$CI->_output ( $output );
		} else {
			echo $output; // Send it to the browser!
		}
		
		log_message ( 'debug', "Final output sent to browser" );
		log_message ( 'debug', "Total execution time: " . $elapsed );
	}
	
	// --------------------------------------------------------------------
	

	/**
	 * Write a Cache File
	 *
	 * @access	public
	 * @return	void
	 */
	function _write_cache($output) {
		$CI = & get_instance ();
		$path = $CI->config->item ( 'cache_path' );
		
		$cache_path = ($path == '') ? APPPATH . 'cache/' : $path;
		
		if (! is_dir ( $cache_path ) or ! is_really_writable ( $cache_path )) {
			log_message ( 'error', "Unable to write cache file: " . $cache_path );
			return;
		}
		
		$uri = $CI->config->item ( 'base_url' ) . $CI->config->item ( 'index_page' ) . $CI->uri->uri_string ();
		
		$cache_path .= md5 ( $uri );
		
		if (! $fp = @fopen ( $cache_path, FOPEN_WRITE_CREATE_DESTRUCTIVE )) {
			log_message ( 'error', "Unable to write cache file: " . $cache_path );
			return;
		}
		
		$expire = time () + ($this->cache_expiration * 60);
		
		if (flock ( $fp, LOCK_EX )) {
			fwrite ( $fp, $expire . 'TS--->' . $output );
			flock ( $fp, LOCK_UN );
		} else {
			log_message ( 'error', "Unable to secure a file lock for file at: " . $cache_path );
			return;
		}
		fclose ( $fp );
		@chmod ( $cache_path, FILE_WRITE_MODE );
		
		log_message ( 'debug', "Cache file written: " . $cache_path );
	}
	
	// --------------------------------------------------------------------
	

	/**
	 * Update/serve a cached file
	 *
	 * @access	public
	 * @return	void
	 */
	function _display_cache(&$CFG, &$URI) {
		$cache_path = ($CFG->item ( 'cache_path' ) == '') ? APPPATH . 'cache/' : $CFG->item ( 'cache_path' );
		
		// Build the file path.  The file name is an MD5 hash of the full URI
		$uri = $CFG->item ( 'base_url' ) . $CFG->item ( 'index_page' ) . $URI->uri_string;
		
		$filepath = $cache_path . md5 ( $uri );
		
		if (! @file_exists ( $filepath )) {
			return FALSE;
		}
		
		if (! $fp = @fopen ( $filepath, FOPEN_READ )) {
			return FALSE;
		}
		
		flock ( $fp, LOCK_SH );
		
		$cache = '';
		if (filesize ( $filepath ) > 0) {
			$cache = fread ( $fp, filesize ( $filepath ) );
		}
		
		flock ( $fp, LOCK_UN );
		fclose ( $fp );
		
		// Strip out the embedded timestamp
		if (! preg_match ( "/(\d+TS--->)/", $cache, $match )) {
			return FALSE;
		}
		
		// Has the file expired? If so we'll delete it.
		if (time () >= trim ( str_replace ( 'TS--->', '', $match ['1'] ) )) {
			if (is_really_writable ( $cache_path )) {
				@unlink ( $filepath );
				log_message ( 'debug', "Cache file has expired. File deleted" );
				return FALSE;
			}
		}
		
		// Display the cache
		$this->_display ( str_replace ( $match ['0'], '', $cache ) );
		log_message ( 'debug', "Cache file is current. Sending it to browser." );
		return TRUE;
	}

}
// END Output Class

/* End of file Output.php */
/* Location: ./system/core/Output.php */